1. Field of the Invention
The present invention relates to a projector. More specifically, the present invention relates to a light cut for a lamp of a projector.
2. Background of the Invention
As the science being developed to another stage, projectors are applied to variable fields, such as the consumption products to high technology products; the application range is being expanded continuously. For instance, the exhibitions for big conference rooms or commercial projecting screens or televisions, all are to cooperate with the presentation contents for instantly showing. Projectors are specially designed for high illumination and clear images on a screen, therefore audiences may acquire a comfortable environment to view. Hence, it is known that such projectors adopt high-power lamps to approach the purposes aforesaid. However, the problem accompanying with the high-power lamp is theventilation for heatgenerating from the lamp. In prior art, an exhausting fan is designed to cool the heat, but the noise produce as well, and an exhausting outlet may let light escapes out of the projector. According to aforesaid, how to effectively block light and reduce noise, further to increase a heat-dissipating rate of the lamp become an important issue for researching and developing in the relevant fields.
Referring to FIG. 1, which shows a lamp 10 and an exhausting outlet louver 11. Generally the lamp 10 consists of a lamp reflector 101 and a burner 102. Due to the burner 102 emitting high illumination for light source, two ways are to approach the purpose of high illumination, one is to adopt the lamp 10 with high-power, the other one is to cover a layer with a high reflection rate by way of electroplating or coating on the interior surface of the lamp reflector 101 to reflect the light emitted from the burner 102. Nevertheless, the partial light from the burner 102 still goes through the lamp reflector 101 to scatter, even the whole lamp 10 is located in the interior of projector and enveloped by a casing. On the other hand, to cool the lamp 10 may have an exhausting fan 12 and an exhausting outlet for draining out heating air. The exhausting outlet 11 is then designed to be placed below the lamp 10, and plural inclined louvers 111 are added on the exhausting outlet 11 to block the light through the lamp reflector 101 going toward the exhausting outlet 11 for preventing escape of the light, but the windage for the exhausting outlet 11 is increased to cause the interference of cooling air moving out, thus the efficiency of heat dissipating is lowered. Along with the condition in prior arts, the only way to figure out the problem is to enhance the fan 12 speed to keep the heat-dissipating efficiency in a good stage; on the other hand, the increase of the noise and the decrease of the fan's life are inevitably produced.